Flashcards
waves and sound
Cards in this deck (12)
- 1wave speed
- 2periodT = 1/ frequency
-time it takes to complete one wave cycle
-inverse of frequency since frequency is number of cycles per second - 3angular frequencyway to express frequency in radians per second
- also 2 pi / T
- 4speed of soundB (bulk modulus) : measure of medium's resistance to compression
- B is largest in solid > liquid > gas so sound travels fastest in solid
- speed of sound in air at 20 C : 343 m/s
- 5Doppler effect- describes the difference between the actual and perceived frequency when source of sound and detector of sound are moving relative to each other
- top sign : moving towards
- 6intensityI = P / a
- power transported per unit area across surface that is perpendicular to wave
- unit : Watt / m^2
- is proportional to amplitude squared and 1/distance squared
- intensity increases over amplitude and decreases over distance - 7sound level- sound level is loudness : how we perceive sound's intensity ; subjective
- I o (threshold for hearing) : 1 x 10^-12 W/m^2 which is softest sound we can hear
- 8change in sound level
- 9beat frequencydifference in frequency between two waves
- 10wavelength of standing wave (strings) frequency of standing wave (strings)- both ends are secured so nodes
n = number of half wavelengths (node to node)
* n = number of antinodes *
- 11wavelength of standing wave (open pipe) frequency of standing wave (open pipe)- both ends are open so antinodes
n = number of half wavelengths (antinode to antinode)
* n = number of nodes * - 12wavelength of standing wave (closed pipe) frequency of standing wave (closed pipe)- closed at one side (node) and open at other (antinode)
- n : number of quarter wavelengths (from node to antinode)
- n must be odd integer
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- physics Flashcards on waves and sound, created by Subin Jang on 12/06/2019.
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- Subin Jang
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